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Tropical Storm Barry Forecast Discussion Number 10
2019-07-12 22:39:20| National Hurricane Center (Atlantic)
Issued at 400 PM CDT Fri Jul 12 2019 000 WTNT42 KNHC 122039 TCDAT2 Tropical Storm Barry Discussion Number 10 NWS National Hurricane Center Miami FL AL022019 400 PM CDT Fri Jul 12 2019 Although the storm continues to look disorganized in satellite imagery, surface observations and data from an Air Force Reserve Hurricane Hunter aircraft indicate that the central pressure has fallen to 993 mb with the maximum winds still near 55 kt. A prominent cloud swirl has rotated more than halfway around the eastern and northern side of the mean center since 17Z, and there were several reports of strong winds in association with this feature. Strong convection persists to the south of the center, but to this point northerly shear has prevented the convection from becoming better organized. The initial motion is now an erratic 300/5. Barry should turn northwestward during the next several hours as it approaches a weakness in the mid-level ridge over the Mississippi Valley, and this motion should bring the center across the central coast of Louisiana between 12-24 h. After landfall, the system should move northward through a break in the ridge until the 72 h point, after which it should recurve northeastward into the westerlies. The guidance envelope has shifted slightly westward since the last advisory, but the shift is not large enough to require significant changes to the forecast track. Thus, the new track forecast again has only minor tweaks from the previous one, and it lies just east of the the various consensus models. Barry continues to strengthen despite the asymmetric convective structure, the shear, and the presence of mid- to upper-level dry air over the northern semicircle. The intensity guidance forecasts continued intensification until landfall, and so will the NHC forecast. While not explicitly shown in the forecast, Barry is expected to become a hurricane near the time it makes landfall between the 12 and 24 h forecasts points. After landfall, the cyclone should steadily weaken, with decay to a remnant low expected to occur in about 72 h and dissipation after 96 h. Key Messages: 1. There is a danger of life-threatening storm surge inundation along the coast of southern and southeastern Louisiana, portions of Lake Pontchartrain, and portions of coastal Mississippi where a Storm Surge Warning is in effect. Water levels are already beginning to rise in these areas, with the peak inundation expected on Saturday. The highest storm surge inundation is expected between Intracoastal City and Shell Beach. 2. The slow movement of Barry will result in a long duration heavy rainfall and flood threat along the central Gulf Coast, across portions of the Lower Mississippi Valley and north into the Tennessee Valley through the weekend into early next week. Flash flooding and river flooding will become increasingly likely, some of which may be life-threatening, especially across portions of southeast Louisiana into Mississippi. 3. Hurricane conditions are expected along a portion of the coast of Louisiana, where a Hurricane Warning is in effect. Tropical storm conditions are expected elsewhere along much of the Louisiana coast and inland across portions of the lower Mississippi Valley where tropical storm warnings are in effect. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 28.7N 90.9W 55 KT 65 MPH 12H 13/0600Z 29.2N 91.3W 60 KT 70 MPH 24H 13/1800Z 30.1N 91.9W 60 KT 70 MPH...INLAND 36H 14/0600Z 31.3N 92.3W 45 KT 50 MPH...INLAND 48H 14/1800Z 32.5N 92.5W 30 KT 35 MPH...INLAND 72H 15/1800Z 35.0N 92.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 16/1800Z 38.0N 91.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 17/1800Z...DISSIPATED $$ Forecaster Beven
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